Study of structural, optical and electrical properties of SnO2 doped TiO2 thin films prepared by a facile Sol-Gel route

This manuscript deals with sol-gel derived SnO2-TiO2 thin films deposited on silicon wafer type Si (100) substrate, which are processed by spin coating technique. Heat treatments of the as-deposited films are then performed at four different temperatures (200, 400, 600, and 800 degrees C). The first characterization via XRD identifies the nano-crystalline phase begins to form at 400 degrees C from the long range order and becomes well crystallized into larger size with the increase of annealing temperature. Morphological and compositional studies of these samples are carried out, followed, for the first time, by spectrophotometric measurement of optical constants (extinction coefficient (k) and refractive index (n)). Then the high-temperature measurement of dielectric properties for which the data interpretation in the form of log-log plots of real and imaginary components of the complex permittivity are found to exhibit universal many body response over a broad frequency range 1 Hz-1 MHz. Different presentations of the universal dielectric behaviour by means of impedance, modulus, and conductivity analyses are given as well.